package  main.java.leetcode.editor.cn;
//2022-03-31 16:50:37
//给你二叉树的根节点 root 和一个整数目标和 targetSum ，找出所有 从根节点到叶子节点 路径总和等于给定目标和的路径。 
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// 叶子节点 是指没有子节点的节点。 
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// 示例 1： 
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//输入：root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22
//输出：[[5,4,11,2],[5,8,4,5]]
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// 示例 2： 
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//输入：root = [1,2,3], targetSum = 5
//输出：[]
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// 示例 3： 
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//输入：root = [1,2], targetSum = 0
//输出：[]
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// 提示： 
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// 树中节点总数在范围 [0, 5000] 内 
// -1000 <= Node.val <= 1000 
// -1000 <= targetSum <= 1000 
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// Related Topics 树 深度优先搜索 回溯 二叉树 
// 👍 706 👎 0

import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

class PathSumIi {
    public static void main(String[] args) {
        //创建该题目的对象方便调用
        Solution solution = new PathSumIi().new Solution();
    }
    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode() {}
        TreeNode(int val) { this.val = val; }
        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }
    //leetcode submit region begin(Prohibit modification and deletion)
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    List<List<Integer>> result = new LinkedList<>();
    Deque<Integer> tree = new LinkedList<>();
    public List<List<Integer>> pathSum(TreeNode root, int targetSum) {
        hasPathSum(root,targetSum);
        return result;
    }
    public void hasPathSum(TreeNode root,int targetSum){
        if(root == null){
            return;
        }
        tree.offerLast(root.val);
        if(root.left == null && root.right == null && targetSum == root.val){
            result.add(new LinkedList<>(tree));
        }
        hasPathSum(root.right,targetSum-root.val);
        hasPathSum(root.left,targetSum-root.val);
        tree.pollLast();
    }
}
//leetcode submit region end(Prohibit modification and deletion)

}
